(53e) Phase Behavior of AB/CD Diblock Copolymer Blends Via Coarse-Gained Simulations

Recent advances in synthetic polymer chemistry have allowed a seemingly unlimited number of possible block polymer architectures and a corresponding increase in interesting phase behavior. By blending various block copolymers, similar increases in interesting phase behavior can be achieved at a substantially reduced cost because of the relative ease of synthesis. In this work, blends of A-B and C-D diblock copolymers are studied using coarse-grained molecular dynamics. Macro-phase separation is prevented by choosing B and C blocks that exhibit a negative χ and therefore favor mixing, thus causing the B-C mixed phase to act like the midblock of an ABC triblock and tether the other blocks together. By using coarse-grained molecular dynamics, phase diagrams are produced as a function of volume fraction and relative χ parameters. The dependence of domain sizes on block length is found, and these results are compared with triblock copolymer phase diagrams.